Cloudlets default to cloning with https

A new option (specific to the registry/GitHub) lets users clone via SSH
instead.  Fixes #126.
progress, but does not yet work.
remove unneeded code from scenario
update doc string to reflect that its used in generate params.
aws provider now just uses boto to communicate with CloudFormation service.
remove awscli as dependency.
add in exmaple helper functions from example code.
added in stub code that could be used in the future.
Merge branch 'master' into 127-cloudlet-without-ssh

Conflicts:
	nepho/cli/cloudlet.py
remove commented out imports
Merge pull request #127 from huit/127-cloudlet-without-ssh

Cloudlets default to cloning with https
Cleaning up PEP8 warnings

Confirmed that aws/boto driver works with iam-poc

still doesn't work with my branch of nepho-example, but this is good
enough to merge
Merge pull request #135 from huit/feature/aws-boto-only

Feature/aws boto only
Merge branch 'master' into feature/integrate-scope

Conflicts:
	nepho/cli/base.py